Vol. 19, No. 33

June 8, 2000

Gene repair success for canine muscular dystrophy

Gene repair, a method of correcting errors in diseased genes, has been found to be successful in treating a canine version of Duchenne muscular dystrophy, according to a research article in the June issue of Nature Biotechnology magazine.

Molecular biologist Eric Kmiec, biological sciences, invented the gene mending technique in 1993. Kmiec assembled a genetic material that has the ability to fuse with a mutant gene and then trigger its natural DNA repair mechanism.

Duchenne muscular dystrophy is the most common form of the disease afflicting children, usually appearing between the ages of 2 and 6 six years old.

Researchers have identified the gene that, when flawed, can result in death by a child's teen years. Because the faulty gene fails to make a version of the muscle protein dystrophin, the sufferer can need a wheelchair by age 12. With gene repair, the code of the mutant gene can be restored so that the body produces dystrophin.

This method was tested in a homologous pre-clinical trial by Richard J. Bartlett and colleagues at the National Institute of Arthritis and Musculoskeletal and Skin Diseases, of the National Institutes of Health, and the University of Missouri.

Bartlett reports in Nature Biotechnology positive results using a single treatment in a selected muscle of a 6-week-old golden retriever puppy afflicted with a canine form of Duchenne muscular dystrophy.

After injecting the affected skeletal muscle of the puppy with Kmiec's gene repair material, known as chimeric RNA/DNA oligonucleotide, the team found the genetic code of the mutant gene was corrected so that the dog's cells produced dystrophin. The effects lasted for 48 weeks.

The hope is the work will translate into treating humans with this inherited disease that affects males.

Bartlett is working closely with Kmiec on doing follow up studies using new designs for these chimeric oligonucleotides.